Since waste water discharged from a kitchen such as feeding center, a restaurant and the like, a meat center, a food/fish processing factory contains fats and fatty oils of animals and plants, the treatment of it is essential, in a feeding center and the like, and the waste water containing fats and fatty oils discharged from the kitchen is flown into a measure which is called as a grease trap via a flow input pipe, where the removal of the waste oil and fat is carried out, and the flowing out of the waste oil and fat to the sewage and the like is prevented.
As for a method of removing waste oil and fat, a method in which waste oil and fat accumulated in the upper portion of the grease trap is collected by a strainer or a net attached on the grease trap, or a method in which waste oil and fat is decomposed by a microorganism and enzyme projected within a grease trap and the like are listed. However, in the case of a method of collecting waste oil and fat by a strainer or net, since the clean-up of strainer or exchange of the net has to be frequently carried out, which is troublesome and the working environment becomes inferior by bad odor or the like, therefore, workers are apt to spare themselves in collecting work. Moreover, since a large amount of waste water containing oil and fat may be flown into the grease trap at a time, a microorganism and enzyme projected into the grease trap is easily flown out from the grease trap, and the waste oil and fat may not be decomposed sufficiently. On the other hand, if the decomposing property of the waste oil and fat is contemplated to enhance, there is a troublesome matter that a microorganism and enzyme have to be refilled, for example, every day and so on. Moreover, the refilling is not only troublesome but also the cost becomes higher. Furthermore, there was a problem that entrusting the collection of the waste oil and fat to a treatment expert service company costs much. Then, the applicant of the present application has proposed a method of treating waste water containing oil and fat by decomposing the waste water containing oil and fat accumulated in the grease trap by means of providing and installing a bioreactor in which an immobilized enzyme is filled in a grease trap in the treatment of waste water containing oil and fat containing waste oil and fat discharged from a kitchen and the like (Japanese Patent Laid-Open No. 2003-225652 gazette).
However, at present, domestically, an extremely large number of grease traps which are required to carry out the troublesome removal working of waste oil and fat have been installed, and if a method described in Japanese Patent Laid-Open No. 2003-225652 gazette is carried out on these grease traps, the use of the grease traps has to be temporarily interrupted and a bioreactor in which an immobilized enzyme has been refilled has to be installed, which is not only inconvenient, but also which requires troublesome installation work. Moreover, in Japanese Patent Laid-Open No. 2003-225652 gazette, it has been disclosed that the treatment of waste oil and fat of waste water containing oil and fat that has been performed under the conventional troublesome and inferior situation is simply and cheaply carried out, however, there is no detailed description such that the treatment of waste oil and fat can be performed using an immobilized enzyme at a further higher decomposition rate.